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Pumping Liquid Refrigerant- what will work?

Hey Guys-

So im working on a new project, and trying to pump liquid refrigerant(134A) with a Delta P of 375 PSI, up to 510 +- Flow rate will be between 14-18 GPM. I am having a difficult time tracking down a pump. At first thoughts, i was looking for a gear pump, but people advised me that would not be the best. I received a quote on a Regen turbine pump for 16K USD. That is way too much for this project. I know vane pumps are used regularly at lower pressures, but i believe that may be the best for my application, if one can accommodate high pressures.
Any thoughts you may have are appreciated.

Re: Pumping Liquid Refrigerant- what will work?

I have seen, almost 20 years back, a Liquid Ammonia pump which was pumping liquid from a atomspheric pressure Ammonia storage tank to 15 Bar user point in fertilizer plant. I think that was a pistone pump (positive displacement). In chemical & fertilizer plants such type of pumps might be used for pumping volatile liquids.

Re: Pumping Liquid Refrigerant- what will work?

I was under the impression that piston pumps would cause irregular pulsations, resulting in problematic fluid-gas? If this is not the case so much, maybe they should work fine. Maybe stacking a centrifugal pump in front of the piston pump to feed it plenty of fluid.

Re: Pumping Liquid Refrigerant- what will work?

I have not used one but asked a supermarket rack manufacturer about them and they told me the installed them on a few systems and all of them are disconnected because there was a problem with flash gas in the liquid line due to the pressure change or something like that.

Re: Pumping Liquid Refrigerant- what will work?

Its only a suggestion but it could avoid an expensive pump to a more standard less expensive pump.

Depending on exactly what you want to achieve if it is possible to have an intermediate transfer vessel.
Usually called a liquid transfer or pump-drum.

1/ First lower pressure 375psi drains into intermediate vessel with a vent back into 375 psi vessel so it freely drains.
2/ Intermediate vessel is isolated from 375psi vessel.
3/ Intermediate vessel is then equalized to 510psi vessel.
4/ After equalization use pump to tranfer liquid with a then very low dp.
5/ when level is decreased stat the cycle over venting intermediate vessel back to 375psi vessel.

Use of low pressure drop non return valves & solenoids essential.
Also a small canned or mag drive pump may be able to be used (no shaft seal)

After saying all that cannot see why a gear pump would not work, the only danger would be possibly lubrication & type of shaft seal.

Re: Pumping Liquid Refrigerant- what will work?

Yea, the intermediate transfer vessel would work, but seems like alot of trouble. I will look more into the viking pumps. Looking at their website, looks like the max case pressure allowable on the Viking vane pumps is 300 PSI. Maybe that will work for the primary pump.
any good centrifugal pumps for refrigerant?

Re: Pumping Liquid Refrigerant- what will work?

generally, we use reciprocating pumps in this case because of cost cutting.In addition, they work well and no problem in it except in summers.They work efficiently for first few hours and then their efficiency decreases.

Re: Pumping Liquid Refrigerant- what will work?

Sumit-
So you would say maybe a CAT pump? By reciprocating, i believe you mean a piston-style. How are the pulsations? Wouldn't a piston pump pull a vacuum on the inlet when stroking? Do you believe that i would be able to use another pump to supply a pressure to the inlet side of the reciprocating pump?

Re: Pumping Liquid Refrigerant- what will work?

As one step its either a piston or a diaphragm pump. Either one would want a centrifugal upstream as an NPSH boost unless your system arrangement has considerable head and subcooling available. A diaphragm is more like wear and erosion resistant and a lot simpler to make chemically compatible.

Both are going to pulsate; though a hydraulic accumulator would tend to take it out.

Only smooth flowing piece would be a side channel or regenerative multi-stage. Both are going to be highly critical to NPSH.

18 GPM at 510 Psi is going to be at least a 15-Hp pump. None of them are going to be cheap.

Re: Pumping Liquid Refrigerant- what will work?

Try calling Hansen Technologies. On their website (hantech.com) they had a hermetic liquid refrigerant pump that can go up to 600 psig. Also, I read about Viking pumps above. Viking makes a very good pump and if you need another option check Tuthill....a competitor to Viking.

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